In a radio access network, such as a 2G, 3G or Long-Term Evolution (LTE) network, a user equipment (UE), such as a smartphone, laptop computer, tablet computer, or the like, may execute one or more applications. The one or more applications reside in a application layer or an upper layer of the UE. The UE applications may generate data, referred to as user-plane data, that is often ultimately destined, via uplink, for a server associated with the UE-based application, or to another destination. A Radio Resource Control (RRC) Connection may be needed for carrying the user-plane data over a radio access network (e.g. Universal Terrestrial Radio Access Network (UTRAN), evolved UMTS Terrestrial Radio Access Network (E-UTRAN), or GSM EDGE Radio Access Network (GERAN)) toward its destination, and possibly in return from the destination to the UE. Radio resource control involves, in one aspect, the establishment, configuration, and/or release of radio access bearers in a wireless network.
User-plane data may be generated by an application in response to user interaction with the application at the UE. This is referred to herein as user-initiated user-plane data (UIUPD). Because a user is likely to be paying attention to the application, the user-plane data may be referred to as “attended” user-plane data. For example, when the application is a web browser, the selection or clicking of a hyperlink by a user may cause the application to generate a Hypertext Transfer Protocol (HTTP) GET message comprising a uniform resource locator (URL) (also known as a uniform resource identifier (URI)) of the desired web page. That message is a form of user-initiated user-plane data.
Alternatively, a UE-based application may generate user-plane data automatically, e.g. in the absence of user interaction with the application for at least a predetermined time period. This is referred to herein as non-user-initiated user-plane data (NUIUPD). For example, applications such as Gmail™, Twitter™, or Facebook™, or other social networking applications, may periodically generate an auto-update message, with a view to maintaining relatively fresh data at the UE application. Such auto-update messages are examples of non-user-initiated user-plane data. Because the user is unlikely to be paying attention to the application, the user-plane data in this case may be referred to as “unattended” user-plane data. The default interval between successive auto-update messages may differ among applications (e.g. it may be 20 minutes for Gmail™, 30 minutes for Twitter™, and 60 minutes for Facebook™). Another example of non-user-initiated user-plane data messages are keep-alive/ping transmissions that are triggered by “always-on” applications, which may utilize an always-on packet data protocol (PDP) context for data exchange with their respective push servers. The UE may use the keep-alive or ping mechanism to prevent the PDP context from being closed by the network. In some cases, non-user-initiated user-plane data messages may be generated by an application while the user interacts with other applications at the UE.
In another example, an application presenting a map at a moving UE 20 may generate an auto-update message, e.g. whenever the application determines that it needs to fetch new map information due to the movement of the UE 20. This can be considered as sensor-initiated user-plane data, as typically the request is generated in response to receiving input from a sensor, such as a GPS sensor in the case of a request to fetch new mapping data because a change in location of the UE has been detected. In this case, the urgency of response may be greater than in the social networking application example, because a user may actually be watching, or depending upon the currency of, the display map data. Therefore, the user-plane data in this case may also be referred to as “attended” user-plane data despite being non-user-initiated.
It is further possible for a non-user-initiated user-plane data message to be generated by an application and then, shortly thereafter, for a user-initiated user-plane data message to be generated, possibly by the same application or by a different application.